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6-2011 Shirking in the National Hockey League Luke D. Cain Union College - Schenectady, NY
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Shirking in the National Hockey League
by
Luke D. Cain
* * * * * * * * *
Submitted in partial fulfillment of the requirements for Honors in the Department of Economics
UNION COLLEGE June, 2011
Abstract
CAIN, LUKE D. Shirking in the National Hockey League Department of Economics, June 2011. Advisor: Stephen Schmidt
Shirking has been examined in baseball and basketball, but never hockey. If Shirking is found to be evident in hockey, then management should give players shorter contracts and should pay a discount price if a long‐term contract is given. The dependent variable for this study is shirking. There are many different independent variables and they are all different measures of performance (except for dummy variables for team and position). Most studies of hockey have minimal measures of performance, which are usually offensive statistics, but I will include defensive statistics as well. The sample for the study is players who participated in the 2007‐08 and 2008‐09 NHL seasons. These players also had to be under a contract that saw them make more than $500,000 during the 2008‐09 campaign. The salary data was compiled from NHLnumbers.com while the statistical data was taken from NHL.com. I am running a five stage regression analysis to test my shirking hypothesis. One possible measurement problem is that there is only data from two seasons, but there are still over 550 players tested. Shirking was not found in the NHL. The more years remaining on a player’s contract does not decrease performance. However, a player’s performance decreases as their likelihood of retirement at the end of their current contract increases. I will refer to the former traditional shirking because that is what most of the literature examines when testing for shirking. I will refer to the latter as non‐traditional shirking.
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Table of Contents
List of Figures and Tables iii Chapter One: Introduction 1 Chapter Two: Background Information 4 A. Anecdotal Shirking Evidence 4 B. Hockey Statistics 4
Chapter Three: Literature Review 9 A. Shirking in the Literature 9 B. Measuring Hockey Performance in the Literature 15
Chapter Four: The Shirking Model 17 A. An Investigation of Why Shirking Occurs 17 B. The Regression Equation 20 C. Determining Costs of Non-Traditional Shirking 27
Chapter Five: Data 29
Chapter Six: Results 33 A. Two Tests of the Shirking Hypothesis 33 B. The Cost of Non-Traditional Shirking 36
Chapter Seven: Discussion 39
A. vs. 39 B. Interpreting Traditional Shirking 40 C. Interpreting Non-Traditional Shirking 42 D. Traditional vs. Non-Traditional Shirking 44 E. Interpreting the Costs of Shirking 44 F. Future Research 45
Chapter Eight: Conclusion 46
Bibliography 48
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List of Figures and Tables
Figure 1: The Utility/Effort Relationship 18
Figure 2: The Effort/Years Remaining Relationship 18
Figure 3: The Age/Performance Relationship 22
Figure 4: Simple Regression Estimates Predicting Probability of a Player’s Last Contract 24
Figure 5: Probit Model Predicting Probability of a Player’s Last Contract 25
Table 1: Descriptive Statistics for 2007‐08 Performance Variables 30
Table 2: Descriptive Statistics for 2008‐09 Performance Variables 31
Table 3: Descriptive Statistics for Player Salaries 31
Table 4: Descriptive Statistics for Retiring, Re‐signing and Current Contract Players 32
Results Table 1: Simple Regression Results on Shirking Using 34
Results Table 2: Simple Regression Results on Shirking Using 35
Results Table 3: Simple Regression Results Determining Value of each Performance 36 Variable
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Chapter 1: Introduction
Professional athletes sign contracts for millions of dollars and are paid regardless of how they perform. This leads many people to believe that players who sign multi-year contracts do not perform as well after signing one because their performance in the short-term will not change their current pay, and they will still have a chance to increase performance when their contract is closer to expiration: “If ever there’s a time for a player to walk the walk, it’s right before he’s about to walk” (Sports Illustrated, as is cited in Krautmann and Solow 2009). This decrease in performance is a result of a decrease in effort and the decrease in effort is known as shirking.
Evidence of shirking has been found in both baseball and basketball, but has never been examined in hockey. Performance in hockey is difficult to measure because there are many intangible assets that make up a player’s performance. Number of points scored is the most important performance variable, which is why high point producers have the highest salaries, but there are many other players who do not produce as many points but are still handsomely rewarded. In this paper I attempt to include measures of intangible assets as well as traditional measures of performance. Using these measures, I found that shirking does not occur in the
National Hockey League (NHL) unless a player is in his last contract before retirement.
Are the findings in this paper correct? This is a function of the methodology and the data, but it should be shown that both areas are solid and properly supported. Another question that arises is the implication of these results. There are questions of what the results mean for managers who have to sign players as well as players who have to negotiate contracts. There is also the dilemma of how much to reduce pay for players who are likely to retire at the end of the contract due to shirking. Each of these issues are discussed and dealt with. Sometimes more
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than one possibility is given because, in some instances, there is more than one solution to the same situation.
I focus the last discussion in this paper on what future researchers should examine. This is the first paper on shirking in the NHL and, as such, the area of study should be developed. I
suggest some avenues for future research and expect other avenues to open.
Chapters two and three examine previous research on shirking and provide background
information for those less familiar with the sport of hockey. Previous research on shirking in
baseball and basketball provide solid models and ideas to help with my analysis of shirking in
hockey. Previous research on performance in the NHL and salary determination provides a
beginning model for evaluating player performance on more factors than simply points. The
background information chapter is an overview for why certain performance variables were
chosen to measure a player’s performance. The importance of each performance variable is
discussed.
Chapters four and five outline the shirking model and the data. In the model chapter I
explain the theory of shirking, its implications, and I include graphical analyses. I then focus on
the five-step regression equation used to determine whether shirking does occur in the NHL. In
the data chapter I discuss where the data came from, what it explains, and how.
Chapter six examines the results of the five-step regression equation. Interpretations are
not made in this chapter; it is simply an outline of the results and whether certain variables were
significant, using a 5% significance level.
Chapters seven and eight discuss why certain results occurred and the implications of
these results. The chapter seven discussions focus on why different results occurred. Chapter
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eight gives advice to both players and managers based on the results. The results can be used in contract negotiations, and I explain how.
This final element of my paper is to determine the cost that teams incur based on shirking. Traditional shirking (decreased performance as years remaining increases) does not occur. Non-traditional shirking (decreased performance as the likelihood of retirement increases) does occur. The determination of the cost analysis will be outlined in the model chapter. The results chapter will display the results and the discussion and conclusion will explain why certain results occurred and their implications.
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Chapter 2: Background Information
A. Anecdotal Shirking Evidence
For decades, people involved in both sports and economics have attempted to determine if a player’s performance deteriorates after signing a long-term contract – if players shirk. An executive for player negotiations with the Cleveland Indians stated in 1986, “The experience of individuals clubs, and the industry as a whole is that for whatever reason, the player’s performance is not the same following the signing of a new multi-year contract” (Butler).
Shirking is often claimed using anecdotal evidence, where an individual player is said to be proof that shirking exists. For example, Ilya Kovalchuk, in the last year of his contract (which was
2009-2010), scored 41 goals and added 44 assists for 85 points. So far this season he is on pace to have only 28 goals and 28 assists (through 59 games). This occurred after he signed a 15 year,
$100 million contract this summer. On the other hand, Alexander Ovechkin, after signing a 13 year $124 million contract, scored 19 more goals than the year before and had one more assist for an increase of 20 points. Many more examples are available of players underachieving and overachieving which suggests that this debate cannot be solved through anecdotal evidence.
B. Hockey Statistics
Statistics in hockey are hard to measure. It is a game unlike almost any other. It is unlike football as there are not frequent starts and stops in the play. It is also unlike baseball where the game is reset after every pitch. Because of these differences, both football and baseball can be dissected, through statistics, with greater precision. For example, in baseball, a pitch is a ball or a strike, the batter either hits the ball or he does not, the fielder either makes the out or makes an error, and when the play is over, everything starts again. Collecting statistics for a sport like
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baseball tends to be easier because many plays in baseball are concrete. Conversely, hockey plays are made “on-the-fly” and there can be many “right” plays in the same situation. The problem of gathering statistical data and measuring individual performance in hockey is less when examining offensive players, but amplified when looking at defensive performance.
Offensive production is measured by awarding the player who puts the puck in the net a goal and the last two players who pass the goal-scorer the puck, assists. Measuring an individual’s ability to prevent the opposing team from scoring is difficult. The variables that I am using to judge performance are points, blocked shots, plus/minus rating, giveaways to takeaway ratio, ice time per game, short-handed ice time per game, face-off percentage, hits and games played.
Points are important because when a team scores more goals than their opponent, they win the game. Although assists are usually seen as less important, without them the goal would not have been scored. Offensive performers are usually the highest paid players on a team.
Blocked shots are important because it means that the player stopped a possible goal.
Also, when a player blocks a shot it means that he was in the proper position; between the man he was guarding and the net. Positional play in hockey is very important but it is virtually impossible to measure, so some statistics, such as blocked shots, will help to measure this otherwise difficult variable.
The plus/minus statistic determines, with a few technicalities, how many goals a player’s team scores when he is on the ice, versus how many are scored against his team when he is on the ice. Every time a player’s team scores when he is on the ice, except while the other team has a power-play (meaning the player’s team has taken a penalty so they have less players on the
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ice), a player is given a plus-1 rating. Every time a goal is scored against a player’s team when he is on the ice, except when the opposing team has a power-play, they are given a minus-1 rating. The problem with this statistic is that a goal may be scored which has nothing to do with a specific player, but that player still receives a plus or a minus. However, over the course of a season, the statistic becomes useful as the goals that are scored, whether for or against, that are not a player’s responsibility, are likely to even-out. This leads to the better, more productive, players having high positive ratings and the less-effective players having less positive ratings.
The giveaway to takeaway ratio is similar to the plus/minus rating. Every time a player has control of the puck and due to his actions, the other team gains control of the puck, that player is penalized with a giveaway. Every time the other team has control of the puck and due to the actions of a certain player they, or their team, gain possession of the puck, that player is awarded with a takeaway. This variable, unlike the plus/minus rating, examines the play of the individual player and not the play of his line-mates or players on the other team. The statistic is important for performance because if one’s team has control of the puck, then they are able to score and the other team is not. The better this ratio is for a player (meaning more takeaways than giveaways), the more often he is gaining possession of the puck for his team, and the better chance they have to win.
Average ice-time per game and short-handed ice-time per game are measures of a player’s offensive and defensive performance. Players with more time on the ice are trusted by their coaches more than players who are not on the ice as much. Sometimes this trust is for the player to score goals, and sometimes it is for players to stop the other team from scoring. The players who receive the most ice-time are usually the ones who are good at both scoring goals and stopping the other team from scoring. Short-handed ice-time per game is the measure of the
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ice-time a player receives while the opposing team is on the power-play (as was discussed above the team that is short-handed has one or two less players on the ice because they have taken penalties). This statistic is almost solely a measure of a player’s defensive ability. Although, on rare occasions, a team will score while they are short-handed, their purpose is to stop the other team from scoring. Because the team has fewer players on the ice, it is more important in these situations to use the best defensive players and thus it is a good measure of defensive performance.
There are two potential problems when looking at ice-time statistics. First, they depend partially upon the subjective judgment of the team’s coach. There is the possibility that the coach is not playing the best players. However, coaches are highly trained individuals with the help of assistant coaches and general managers to determine who should be playing the most.
Therefore, it is likely that the coaches are using their personnel correctly. The second potential problem is that the amount or ice-time a player receives depends upon how strong his team is.
An average player in the league will receive more ice-time if he is on a below average team than if he is on an above average team. The individual does not change, but the circumstances he is in lead to a perceived increase or decrease in performance.
Face-off percentage is a statistic that is usually only relevant for centers because they take the majority of face-offs. To start every period, following every goal, and after every whistle in a hockey game there is a face-off. As soon as the referee drops the puck for a face-off, the game continues until the next whistle. Face-offs are important because the team that wins the face-off gains possession of the puck, meaning their team has the ability to score while the other team does not.
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The amount of hits that a player delivers is a good statistic for a player’s intangible assets and because both offensive and defensive players deliver hits, the statistic is relevant for all players. For example, Alexander Ovechkin, one of the top goal scorers and point producers in the NHL is also one of the hardest, and most frequent, hitters. Also, there are many defensive forwards who are very physical and deliver hits of a regular basis. Hits are important because they can ‘wear a team down’ over the course of a game and season, they can intimidate, and they make scoring more difficult for the opposition. Therefore, the more a player delivers hits, the more valuable he is to his team.
Games Played is another statistic that depends upon coaches or management decisions, but this paper assumes that the coach is playing the right players, and the players who are not as effective, or are hurt, are not being played.
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Chapter 3: Literature Review
Currently, there are no papers that examine shirking in the National Hockey League.
Literature available on shirking in professional sports focuses on Major League Baseball (MLB), and the National Basketball Association (NBA). The conclusions reached through the MLB and
NBA papers are mixed – some find that there is no shirking effect; others find that there is a shirking effect; still others argue that it depends on the measure of performance used (some only use basic statistics, while others use a more in-depth performance measure).
A. Shirking in the Literature
The papers that find shirking to be nonexistent have done so using more than one approach. Maxcy et al (2002) examines players in the last year of their current baseball contract and their first year of a long-term contract. These players are then compared to players of similar skill around the league. Skill is measured through expected performance, which is derived from a player’s performance over the past three seasons. If performance has been declining, performance expectations drop. If performance has been improving, performance expectations rise. By comparing players who are in the year immediately before or after an expired contract, to others of similar skill, the sample size increases dramatically. No evidence of shirking was found, but this paper relied on the ability to determine which players in the league had similar skill. This problem is magnified in hockey because players of the same skill can perform differently depending on the ability of the players on their team and their line-mates.
Furthermore, different teams have different philosophies, some of which are more defensive and others which are more offensive. Players who are in an offensive system are more likely to have greater offensive production than a player of comparable skill in a more defensive system. A rough example of these differences in philosophy is how a coach expects his team to win. An
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offensive-minded coach wants his team to win by scoring lots of goals, while defensive-minded
coaches want to win by limiting the amount of goals the opposition scores. Shown here is that
hockey players of similar skill should perform differently based on circumstances.
One interesting aspect of the Maxcy et al (2002) paper is that although there is no evidence of shirking when looking at performance, players who are near the end of their contracts tend to play more and do not sit out as much due to injuries. This suggests that either players who are near the end of their contracts are more willing to play through minor bumps and bruises, or that coaches and management push these players to play injured. If the former is true, then the players examined do shirk by taking more games off for minor injuries. If the latter is true, then coaches and management are much more careful with the players that they are invested in for the long term and less careful with players who are near the end of their contracts. Both possibilities suggest a lack of morality in the sports world; however, it is outside the parameters of this study to determine why players with longer contracts miss more games due to injury.
Another paper finding no evidence of shirking in MLB is Krautmann (1990). He uses a more theoretical approach and although he does use statistics, he does not use regression analyses and has a sample size of only 110. He believes that players and management want to sign a contract after an above average season. The player wants to sign a contract after one of these “good” seasons because he wants to “cash-in” on his improved performance. Management wants to sign the player because they expect that these above average seasons will continue into the future and they want to secure their asset (player). However, the player is more likely to return to his mean in the year immediately following an above average season. After the long contract, or contract extension, is signed, and the player does return to his mean, he is accused of shirking.
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This paper determines if a player is truly over-performing or under-performing based on an analysis of the standard deviations of his historical performance. Any performance by a player within two standard deviations of his mean is not considered shirking or over- performance but is rather considered regular fluctuation around the mean. Although the theory behind this is strong, the author does not take into consideration the effects of experience and age, which affect a player’s performance over time. Also, regression analyses are a better method to determine whether shirking is an invention, or whether it is a real phenomenon.
Regression analyses are better because they can hold constant other variables, such as age, when determining if a player’s fluctuations are within two standard deviations, while looking at the data does not allow for control of other variables.
Marburger (2003) argues that the introduction of free agency in 1976 (allowing players more negotiation power) led to a shift in property rights from the owners to the players. He finds no evidence of shirking for those players who sign contracts longer than 2 years. However,
Marburger did find that players, since the change in property rights, who received only 1 and 2 year contracts outperformed players with the same contract length from before property rights were switched. So, although shirking is not found in this paper, there is evidence of opportunistic behavior by players due to a greater incentive as their contract is set to expire; free- agents can negotiate with multiple teams and thus they can find themselves the best deal. Before the shift in property rights, players could not do this. Therefore, performing at a high level one or two years before a contract expires can be very rewarding financially. My paper examines performance depending on how many years a player has remaining on his contract. If
Marburger’s paper had done the same, then perhaps they would have found evidence of shirking in the first few years of a long-term contract. This would be true because players are performing
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better with short contracts and thus they should be able to perform better with long contracts.
Using this reasoning, players were shirking before the change in property rights in 1976, and continue to do so today. It just is not transparent until it is compared to performance when a player is in the final year or two of their contract. Both of these papers, Marburger (2003) and
Maxcy et al (2002), do not find any evidence of shirking when examining performance, but they do find differences between players who have more than 2 years remaining on a contract and players who do not.
Articles by Krautmann and Solow (2009), and Krautmann and Oppenheimer (2002), both written about MLB, find that players shirk more as the length of a contract increases. Krautmann and Oppenheimer find that the coefficient of performance on length was negative and thus a player’s performance decreases as length of a contract increases - a decrease of more than 30% was found. When length was not included in the regressions, there was no evidence of shirking.
Krautmann and Solow used a similar approach as they examined performance over the length of the entire contract. They found that the fewer years a player had remaining on a contract, the less the player shirked. The only time this is not true is when a player is likely to retire. When a player is likely to retire, they have no incentive to reduce shirking as their contract is set to expire
According to Krautmann and Solow, there is a linear relationship between shirking and the number of years remaining on a player’s contract. Whether this holds true in hockey is unknown. My paper will follow the Krautmann and Solow framework and examine player performance and the number of years remaining on a contract. This would have implications for salary negotiations. Knowing that performance decreases with contract length may be helpful; knowing how performance changes over the course of a contract is more helpful.
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Krautmann and Oppenheimer (2002) state that the best players are the ones who receive
the most money and the longest contracts. I argue that the best players also receive a premium
for being one of a handful of elite players in the league. For this reason a premium is paid to
them because they attract more fans, they make the players around them better, and they can be
as productive as two average players. In the 2009/2010 NHL season only four players had more than 100 points, while the 100th leading scorer in the league had 50 points (there are
approximately 600 players who play regularly in the NHL each season). So, one player who
scores more than 100 points in a season is, using a very raw and basic measure of performance,
more than twice as valuable as two players who are in the top 15th percentile for points. In other
words, it takes two well-above average players to produce as much as one elite player. Eighteen
players (excluding goalies) play each game. Having one elite player who produces double while only using one roster position is very valuable.
However, theoretically, players should be willing to accept a lower salary as the length of
their contract increases. The player assumes less risk and has greater security the longer the
contract. A drop in production or a serious injury can end a player’s career, but they still get
paid the remainder of their contract. Buying this security should result in the player receiving a
lower salary.
Two factors are involved when examining long-term contracts. First, players who
receive these contracts are usually the best players and are paid a premium. Second, players
should give up salary to have the security of a longer contract. Disentangling these opposing
forces is a study in itself which is why I do not follow the format of Krautmann and
Oppenheimer who look at the return to performance and contract length. Instead, I follow the
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Krautmann and Solow approach and will examine performance depending on how many years
remain on a player’s contract.
The other option when measuring shirking is to examine a player’s performance the year
before a contract expires and the year after a new contract is signed. Stiroh (2007) took this
approach and applied it to the NBA. Stiroh found that shirking does occur in basketball;
performance rises in the last year of a player’s contract and falls the year following the signing of
a new contract. Although these findings are important, I want to know the magnitude of shirking as an additional year is added to a contract, not just that performance increases or decreases in the year prior to, or after, the expiration of a contract. Stiroh’s paper is simply an illustration of
another method to determine if athletes shirk but it does not answer the question that my paper
poses.
Two papers determine that the existence of shirking is dependent upon how performance
is measured. Berri and Krautmann (2006) studied the NBA and found that, using traditional
measures of performance such as points, assists, rebounds etc., shirking was found. However, if
performance is measured using a more economic model, that measures the magnitude that each
of these statistics has on a team’s winning percentage, shirking was not found. Conversely,
Krautmann and Donley (2009) examined shirking in MLB. They found that using the traditional
measures of performance, namely OPS (on-base % plus slugging average), shirking was not
found, but when using a more economic measure, a combination of Marginal Physical Product
and Marginal Revenue, shirking was found. Determining an economic measure of a hockey
player’s performance would be its own study and thus, this paper will use traditional measures of
performance. However, literature written on hockey leaves out some less obvious but very
important measures of performance. By including these other measures, I hope to gain a truer
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model of a player’s performance and should be able to come to the proper conclusion on shirking
in the NHL.
The model developed by Krautmann and Solow (2009) has four main parts; the first
looks at the relationship between performance and experience; the second is a measure of
shirking based on the player’s past performance and how another year of experience will either
help or hinder them; the third examines a player’s likelihood of retirement. Finally, all three
parts of the model are brought together to determine if a player shirks and the degree that it occurs. It also tests whether this changes if the player is planning on retiring at the end of their contract. A more in-depth explanation of the model is given in the Regression Equation section
(4.B).
B. Measuring Hockey Performance in the Literature
The last important pieces of literature to my subject are the papers that examine salary determination and, indirectly, performance in hockey. It is hard to judge performance in hockey using statistics because of the “flowing” nature of the game. There are many intricacies that are hard to put into a statistic, such as good positioning. Past research by Curme and Daugherty
(2004), Lambrinos and Ashman (2007) and Jones and Walsh (1988) have focused on the determinants of a hockey player’s salary. The determinants of salary should be strongly related to the determinants of a player’s performance. These papers focus mostly on goals, assists and penalty minutes (there are other variables such as how many times a player played in the all-star game, but these variables only affect salary, not performance). The studies do not include hits, blocked shots, plus/minus rating, faceoff percentage, giveaway to takeaway ratio, ice time statistics or games played. Statistics that only examine points are good at measuring offensive
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performance, but defensive players excel in other areas. In Lambrinos and Ashman’s paper
(2007), the variables used explain 68% of forward’s salaries but only 57% of defensemen
salaries. The extra variables that I have included should be able to explain a greater percentage
of both offensive and defensive player’s performance.
The Lambrinos and Ashman paper has a more sophisticated list of variables that affect
salaries in the NHL than the other papers on the topic. On top of goals, assists and penalty minutes, they include power-play goals, game-winning goals and plus/minus. My measure of performance does not include penalty minutes, power-play goals and game-winning goals. A team’s enforcer is paid to fight and take penalties, but for the majority of players, taking a penalty does not help the team and should not be considered positive performance. However, it cannot be considered negative performance because, as was just mentioned, some players are supposed to take penalties for intimidation purposes. Game-winning goals and power-play goals are not included because the correlation between the number of goals a player scores and their power-play and game-winning goals is very high. The better goal-scorers are usually used on power-plays, so they should have more power-play goals. Also, game-winning goals can be scored at any point during a game. For example, if a player scores the first goal of the game in the first period, and the opposing team does not score for the entire game, the player who scored
the first goal is awarded a game-winning goal. However, the fact that he was awarded a game- winning goal is, in part, due to the opposing team not scoring. Sometimes goals are scored to break a tie near the end of a game, and players who tend to score those goals are more valuable because they play better under pressure, but there are no statistics measuring that phenomenon.
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Chapter 4: The Shirking Model
A. An Investigation of Why Shirking Occurs
Players in the National Hockey League are paid their marginal revenue product. Value is given to different measures of performance and, based on this performance, a contract is offered.
For example, goals are highly valued, so the player who scores a lot of goals has a high marginal product resulting in a high salary. However, while a player’s marginal product changes over the course of his contract, his salary does not. The shirking model states that a player’s marginal product will be greatest in the year immediately preceding the expiration of a contract. It also states that their marginal product will decrease the further the player is away from their contract expiring.
Shirking occurs because effort causes negative utility, shown in Figure 1. The graph shows that an increase in effort results in a decrease in utility. This model suggests that for a player to maximize utility, effort will be decreased.
Using the same theory as Krautmann (1990), that management and owners are short- sighted, a player’s effort will decrease as the amount of years remaining on a contract increases.
This is shown in Figure 2.
This decrease in effort is evident not only in games, but also in practice, workouts and focus level. Players decrease effort because their contracts are almost entirely based on a fixed salary. Most players do not have substantial performance bonuses in their contracts, which removes the incentive to exert maximum effort. Players who exert maximum effort and increase their performance do not receive an increase in salary and players who exert minimum effort and decrease their performance do not receive a decrease in salary. With no incentive package
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Figure 1
Figure 2
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present, players are thought to display opportunistic behavior and exert less than maximum
effort. This decrease in effort should increase as the years remaining on a player’s contract
increases.
As a player gets closer to the expiration of a contract, they exert more effort. In the year
immediately preceding the expiration of a contract, maximum effort is exerted. General
Managers pay for future performance, not past performance, which adds to the situation. The
best predictor of future performance is past performance and, to be more direct, the best predictor is last year’s performance. Theoretically, although the performance of a player over the course of his entire contract may play some role in his next contract, greatest weight should be given to the year immediately preceding the signing of a new contract.
Intuitively, if a general manager is wondering how a certain player will perform next season, he is going to give more weight to the season that was just completed, as opposed to a season five years ago. Over five years many factors change such as experience, age and skill development. These changes are usually subtle when examined from one year to the next but more definitive when looked at over five years. However, the year preceding the new contract is still heavily weighted as it gives the best indication of what the future performance will be.
When recent seasons are more heavily weighted the player can mask poor performances in past seasons with good performance in the last year of the contract. This gives the player the ability to shirk early in a contract, and improve as the contract comes closer to expiration.
The only time the last season played should not be heavily weighted in contract negotiations is when the player was injured. In this case, the most weight should be given to the
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player’s last full season played. However, an injury that reduces the ability of the player, or is seen as recurrent, is considered in the contract negotiations.
To truly maximize a salary, maximum effort needs to be exerted over the course of the entire contract. While early years of the contract are not weighted as heavily as the final year, they are considered. Most players, like most people, discount the future and a small increase in future salary (for players with long-term contracts), is not worth an increase in effort now. This creates a double effect working toward the player shirking. The further a player is away from the expiration of the contract, the less that year will affect the salary of the next contract that is signed. Compounding that with the human inclination to discount the future, and the player is more likely to shirk the further they are from the end of the contract.
The final intricacy of the shirking model deals with the players who have plans for retirement at the expiration of their contract. These players have no incentive to increase effort as their contract is set to expire because they will not sign a new contract. Therefore, they can shirk at the same rate over the course of the entire contract.
B. Regression Equation
I am using the same regression equation that Krautmann and Solow (2009) used in their paper. At the most basic level, shirking is the deviation of a player’s expected performance,
E(PERFt+1), from their actual performance, PERFt+1. The following is the formal equation:
Shirkt = E(PERFt+1) – PERFt+1 (1)
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If a player’s actual performance is less than their expected performance, then they are said to be
shirking. However, if a player’s performance is greater than their expected performance then
they overachieved, or they negatively shirked.
A player’s actual performance is determined by looking at their statistics, but determining
the expected performance is more difficult. Expected performance is a function of a player’s
age, injury history, and position. Multiple regressions have to be run in order to reach a player’s
expected performance. First, estimates must be made of player’s performance based on age
(Krautmann and Solow use experience instead of age but the two are basically measuring the
same effect), and other variables that can have an effect on performance, which in the case of
hockey, is position:
2 Perft = β0 + β1 AGEt + β2 AGEt + β3 POSt + Єt (2)
The effect of age has two opposing forces. As a player gets older, experience is gained, skills are
perfected and positioning and “tricks” are learned and developed. On the other hand, as a player
ages, the effects of another year of hockey start to “wear down” a player physically making them
more prone to injuries and they can be perceived as fragile. Also, their reaction time usually
diminishes. These two, opposing forces, lead to the assumption that age has a parabolic shape in
terms of performance.
When a player is young, the effect of another year in the league gives the player a great deal of valuable experience and the negative effect of being one year older is almost negligent.
In fact, the extra year may allow the player to develop more physically. The reason that age- squared is present in the equation is because after a certain point, the negative effects of being one year older outweighs the positive effects of having another year of experience. The graph of
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a player’s performance against his age should be a parabola. The time when a player’s performance peaks is considered a player’s “prime” and in hockey, players are thought to be in their prime in their mid to late 20’s. The nature of the parabola is that at the beginning of a
career the positive effects of an extra year’s experience greatly outweigh the negative effects of
being one year older. The distance between these two effects diminishes until they are equal as
is shown in Figure 3. This occurs at the peak of the parabola. Each year after the peak, the
negative effects of being one year older outweigh an extra year of experience and a player’s
performance deteriorates.
Position is also included in this equation because different positions are more likely to
excel in different performance statistics. For example, forwards are more likely to score goals
while defensemen are more likely to block shots and get hits. In addition, defensemen usually
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get more ice-time than forwards because teams normally dress only three lines of defensemen
while there are four lines of forwards. Including this variable should control for the changes in
performance, based on position.
There are many performance variables, so regression (2) has to be run for each
performance statistic to get the age and position effect. Once these estimates are determined, the
effect of one more year of performance is determined for each performance statistic. An increase in age of one year has the following effect based on equation (2):